1. Field of the Invention
The invention relates generally to integrated circuit design.
2. Background
The energy requirements of an integrated circuit chip or die is a primary concern to chip designers as is the electrical requirement and function of chip or die packages and their relationship with a printed circuit board. Correctly supplying desired supply voltages to a chip or a package requires careful modeling of the electrical characteristics of the chip or package.
A design group typically designs how a package substrate is laid out with vias, interconnects, pins, etc. following a certain envelope of constraints as guidance (e.g., size of package, number of connecting pins, vias, interconnects, etc.). Once the die and a package for the die are designed, the design is electrically simulated. The simulation involves evaluation of, among other things, the electrical characteristics (capacitance, inductance, resistance, etc.) of, for example, the package.
In a typical chip package, there can be several power/ground planes or networks. Accurate package modeling generally requires modeling of each plane in x, y, and z dimension. Modeling according to a cell-based (e.g., spreadsheet) representation is described in xe2x80x9cModeling the Power Rails in Leading Edge Microprocessor Packages,xe2x80x9d Michalka, T. L., 1998 Electronic Components and Technology Conference, pp. 598-604. The reference teaches a spreadsheet-style file format with various planes of a chip or package represented by electrical characteristics of nodes of that plane, the cells of a spreadsheet generally corresponding to the nodes of a plane. For a single plane, the cell-based representation will actually have three components, the electrical characteristics attributable to an x-dimension, the electrical characteristics attributable to a y-dimension, and the electrical characteristics attributable to a z-dimension, i.e., three spreadsheets.
Once a model such as described above is created by, for example, a representative spreadsheet, the model is simulated to analyze the electrical characteristics of the individual cells of the spreadsheet (generally corresponding to the nodes of a plane). One way of analyzing the model is through the use of a simulation engine that may form part of an electronic design automation (EDA) system, such as HSPICE(trademark) commercially available from Avant! of Fremont, Calif. or ADS(trademark) from Hewlett Packard Corporation of Palo Alto, Calif. The simulation engine constitutes a software tool that aids in the development of complex electronic systems. The simulation engine, in this embodiment, evaluates the electrical characteristics of a node or cell for, among other things, compliance with Kirchoff""s law or Conservation of Energy.
One problem in many modeling systems is that the file format representation of the model is not compatible with the file format of the simulation engine. Thus, to execute the simulation engine, the model must be converted by an operator into an executable file format. Such conversion is usually accomplished by manually re-entering the input data into a file format that the simulation engine can execute. This presents the possibility of introducing errors into the data and delays the design process, particularly where there are a large number of spreadsheet plane models each with potentially thousands of cell data that must be re-entered. What is needed is a technique to improve the accuracy and efficiency of this conversion.